From 0ca42dbdbe5849e1cae9f0c9039f14ae0a0f35ba Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Sat, 9 May 2015 17:26:36 +0800
Subject: [PATCH] runtime/dds: send one FUD per command in a batch, compensate
 POW

---
 soc/runtime/dds.c | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/soc/runtime/dds.c b/soc/runtime/dds.c
index 2429eb2b6..fc871fa26 100644
--- a/soc/runtime/dds.c
+++ b/soc/runtime/dds.c
@@ -6,8 +6,8 @@
 #include "dds.h"
 
 #define DURATION_WRITE 5
-#define DURATION_INIT (8*DURATION_WRITE)
-#define DURATION_PROGRAM (8*DURATION_WRITE)
+#define DURATION_INIT (7*DURATION_WRITE) /* not counting FUD */
+#define DURATION_PROGRAM (8*DURATION_WRITE) /* not counting FUD */
 
 #define DDS_WRITE(addr, data) do { \
         rtio_o_address_write(addr); \
@@ -25,7 +25,7 @@ void dds_init_all(void)
     now = rtio_get_counter() + 10000;
     for(i=0;i<DDS_CHANNEL_COUNT;i++) {
         dds_init(now, i);
-        now += DURATION_INIT;
+        now += DURATION_INIT + DURATION_WRITE; /* + FUD time */
     }
     while(rtio_get_counter() < now);
 }
@@ -50,7 +50,7 @@ void dds_init(long long int timestamp, int channel)
     DDS_WRITE(DDS_FUD, 0);
 }
 
-static void dds_set_one(long long int now, long long int timestamp, int channel,
+static void dds_set_one(long long int now, long long int ref_time, int channel,
     unsigned int ftw, unsigned int pow, int phase_mode)
 {
     DDS_WRITE(DDS_GPIO, channel);
@@ -67,11 +67,19 @@ static void dds_set_one(long long int now, long long int timestamp, int channel,
     DDS_WRITE(DDS_FTW2, (ftw >> 16) & 0xff);
     DDS_WRITE(DDS_FTW3, (ftw >> 24) & 0xff);
 
+    /* We assume that the RTIO clock is DDS SYNCLK */
     if(phase_mode == PHASE_MODE_TRACKING)
-        /* We assume that the RTIO clock is DDS SYNCLK */
-        pow += (timestamp >> RTIO_FINE_TS_WIDTH)*ftw >> 18;
+        pow += (ref_time >> RTIO_FINE_TS_WIDTH)*ftw >> 18;
+    if(phase_mode != PHASE_MODE_CONTINUOUS) {
+        long long int fud_time;
+
+        fud_time = now + 2*DURATION_WRITE;
+        pow -= ((ref_time - fud_time) >> RTIO_FINE_TS_WIDTH)*ftw >> 18;
+    }
+
     DDS_WRITE(DDS_POW0, pow & 0xff);
     DDS_WRITE(DDS_POW1, (pow >> 8) & 0x3f);
+    DDS_WRITE(DDS_FUD, 0);
 }
 
 struct dds_set_params {
@@ -83,7 +91,7 @@ struct dds_set_params {
 
 static int batch_mode;
 static int batch_count;
-static long long int batch_fud_time;
+static long long int batch_ref_time;
 static struct dds_set_params batch[DDS_MAX_BATCH];
 
 void dds_batch_enter(long long int timestamp)
@@ -92,7 +100,7 @@ void dds_batch_enter(long long int timestamp)
         exception_raise(EID_DDS_BATCH_ERROR);
     batch_mode = 1;
     batch_count = 0;
-    batch_fud_time = timestamp;
+    batch_ref_time = timestamp;
 }
 
 void dds_batch_exit(void)
@@ -103,13 +111,13 @@ void dds_batch_exit(void)
     if(!batch_mode)
         exception_raise(EID_DDS_BATCH_ERROR);
     rtio_chan_sel_write(RTIO_DDS_CHANNEL);
-    now = batch_fud_time - batch_count*DURATION_PROGRAM;
+    /* + FUD time */
+    now = batch_ref_time - batch_count*(DURATION_PROGRAM + DURATION_WRITE);
     for(i=0;i<batch_count;i++) {
-        dds_set_one(now, batch_fud_time,
+        dds_set_one(now, batch_ref_time,
             batch[i].channel, batch[i].ftw, batch[i].pow, batch[i].phase_mode);
-        now += DURATION_PROGRAM;
+        now += DURATION_PROGRAM + DURATION_WRITE;
     }
-    DDS_WRITE(DDS_FUD, 0);
     batch_mode = 0;
 }
 
@@ -126,11 +134,7 @@ void dds_set(long long int timestamp, int channel,
         batch[batch_count].phase_mode = phase_mode;
         batch_count++;
     } else {
-        long long int now;
-
         rtio_chan_sel_write(RTIO_DDS_CHANNEL);
         dds_set_one(timestamp - DURATION_PROGRAM, timestamp, channel, ftw, pow, phase_mode);
-        now = timestamp;
-        DDS_WRITE(DDS_FUD, 0);
     }
 }